Combusting device for generation of a combustion gas

Abstract

A device comprising a perforated housing containing therein pellets of a chemical composition which undergoes self-sustaining combustion with generation of a combustion gas and an initiator attached to the housing to ignite the pellets. To prevent breaking of the pellets resulting from their movements in the housing, a hollow and resilient retainer member is placed in the housing such that the initiator is exposed to the interior of the retainer and that the pellets are spaced from the initiator by the retainer and held under a compressive force by the resiliency of the retainer. The retainer has openings which allow a gas to pass therethrough but do not allow the pellets to pass therethrough. A helical spring and a perforated bellows are examples of the retainer.

What is claimed is: 
     
       1. A combustion device comprising: a housing defining therein a combustion chamber;   a plurality of pellets of a chemical composition, which undergoes self-sustaining combustion with generation of a combustion gas which may be in the form of flame, disposed in the combustion chamber, the housing having at least one aperture through which the combustion gas jets out of the housing;   an initiator for ignition of the pellets attached to the housing so as to be exposed to the combustion chamber;   a helical spring placed in the combustion chamber in such an arrangement that one end of the helical spring rests on a wall of the combustion chamber, that the initiator is exposed to the interior of the helical spring and that the pellets are entirely spaced from the initiator by the helical spring and held under a compressive force by resiliency of the helical spring, the pitch of the helical spring being small enough to prevent each of the pellets from passing through the gaps of the helical spring; and   plug means engaged with the other end of the helical spring for preventing each of the pellets from entering the interior of the helical spring through an opening at said other end of the helical spring.   
     
     
       2. A combustion device according to claim 1, wherein said helical spring is a generally cylindrical helical spring. 
     
     
       3. A combustion device according to claim 1, wherein said helical spring is a generally conical helical spring of which the wider end rests on said wall of the combustion chamber. 
     
     
       4. A combustion device comprising: a housing defining therein a combustion chamber;   a plurality of pellets of a chemical composition, which undergoes self-sustaining combustion with generation of a combustion gas which may be in the form of flame, disposed in the combustion chamber, the housing having at least one aperture through which the combustion gas jets out of the housing;   an initiator for ignition of the pellets attached to the housing so as to be exposed to the combustion chamber;   a helical spring placed in the combustion chamber in such an arrangement that one end of the helical spring rests on a wall of the combustion chamber, that the initiator is exposed to the interior of the helical spring and that the pellets are entirely spaced from the initiator by the helical spring and held under a compressive force by resiliency of the helical spring, the pitch of the helical spring being small enough to prevent each of the pellets from passing through the gaps of the helical spring; and   a plug fitted into the other end of the helical spring.   
     
     
       5. A combustion device according to claim 4, wherein said helical spring is a generally cylindrical helical spring. 
     
     
       6. A combustion device according to claim 4, wherein said helical spring is a generally conical helical spring. 
     
     
       7. A combustion device according to claim 5 or 6, wherein said combustion chamber is a cylindrical chamber, said helical spring being arranged substantially concentrically with said combustion chamber. 
     
     
       8. A combustion device according to claim 4, wherein said plug is made of a soft and incombustible material and has a gas permeable structure. 
     
     
       9. A combustion device comprising: a housing defining therein a combustion chamber;   a plurality of pellets of a chemical composition, which undergoes self-sustaining combustion with generation of a combustion gas which may be in the form of flame, disposed in the combustion chamber, the housing having at least one aperture through which the combustion gas jets out of the housing;   an initiator for ignition of the pellets attached to the housing so as to be exposed to the combustion chamber;   a helical spring placed in the combustion chamber in such an arrangment that one end of the helical spring rests on a wall of the combustion chamber, that the initiator is exposed to the interior of the helical spring and that the pellets are entirely spaced from the initiator by the helical spring and held under a compressive force by resiliency of the helical spring, the pitch of the helical spring being small enough to prevent each of the pellets from passing through the gaps of the helical spring; and   another helical spring disposed in the interior of said helical spring, one end of said another helical spring being engaged with said other end of said helical spring, the other end of said another helical spring being rested on one end of said initiator, the inner diameter of said another helical spring at said one end being small enough to prevent each of said pellets to pass therethrough.   
     
     
       10. A combustion device comprising: a housing defining therein a combustion chamber;   a plurality of pellets of a chemical composition, which undergoes self-sustaining combustion with generation of a combustion gas which may be in the form of flame, disposed in the combustion chamber, the housing having at least one aperture through which the combustion gas jets out of the housing;   an initiator for ignition of the pellets attached to the housing so as to be exposed to the combustion chamber;   a generally conical first helical spring placed in the combustion chamber in such an arrangement that a wider end of the first helical spring rests on a wall of the combustion chamber, that the initiator is exposed to the interior of the first helical spring and that the pellets are entirely spaced from the initiator by the first helical spring, the pitch of the first helical spring being small enough to prevent each of the pellets from passing through the gaps of the first helical spring; and a second helical spring disposed in the interior of the first helical spring substantially coaxially, one end of said second helical spring being engaged with a narrower end of said first helical spring, the opening of said end of said second helical spring being narrow enough to prevent each of said pellets from passing therethrough.   
     
     
       11. A combustion device according to claim 10, wherein said second helical spring is a generally conical helical spring. 
     
     
       12. A combustion device according to claim 11, wherein said combustion chamber is a cylindrical chamber, said first and second helical springs being arranged substantially concentrically with said combustion chamber.